[A resected case of well-differentiated adenocarcinoma simulating fetal lung tubules which is a variant of pulmonary blastoma].

A case of well-differentiated adenocarcinoma simulating fetal lung tubules which is a variant of pulmonary blastoma is reported. A 31-year-old female with an abnormal shadow in the right upper lung field detected by chest X-P during a follow-up for sarcoidosis during pregnancy underwent right upper lobectomy. Post operative histological diagnosis was well-differentiated adenocarcinoma simulating fetal lung tubules. This tumor might be a variant of pulmonary blastoma lacking the sarcomatous features and showing one-sided development of the epithelial component. However, it has been reported by various names, and classifications of pulmonary blastoma differed slightly depending on the reporter. There are also some discrepancies in the clinical course and prognosis of the tumor. Therefore it is considered that further examination of this tumor is necessary.